Telephone system



Nov. 14, 1939. B, KUDRNA 2,179,723

TELEPHONE SYSTEM Filed Feb. 16, 1938 INVENTOR, BENEDIKT KUDRNA ATTORNF'V Patented Nov. 14, 1939 UNITED STATES PATENT orrlcr.`

TELEPHONE SYSTEM Application February 16, 1938, Serial No. 190,678 In Germany March 5, 1937 4 Claims.

'I'he invention relates to a circuit arrangement for correcting impulses in remote control systems and in particular telephone systems. Various arrangements of this sort are already known but all these have the disadvantage that a considerable number of relays is required. Thus the known arrangements in addition to the impulse receiving relay and the impulse transmitting relay normally require a number and at any rate at least one auxiliary relay.

The invention aims at reducing still further the number of switching means and achieves this object in that the correction of the impulses is effected by the impulse receiving relay and the impulse transmitting relay which so mutually control one another that the receiving relay energized over the line energizes the transmitting relay in a local circuit, whereupon the transmitting relay disconnects the receiving relay from the line and connects itself to the line circuit in place thereof.

The attached drawing represents an embodiment of the invention. The correcting device according to the invention is arranged in the repeater Uel, which is disposed at the outgoing end of a connecting line VL. The repeater is seized when a calling subscriber establishes a call over a preselector VW and a final selector LW. The final selector is constructed as a socalled nal selector with switching through facilities in order to make it possible in small exchanges to pass to another exchange over a connecting line. When the repeater Ue! is seized over the nal selec-tor LW relay A energizes over the closed loop to the calling subscriber in the following circuit: earth, winding III, winding II of relay A, contact 6h, wiper b of the iinal selector LW and of the preselector VW, the subscribers loop, wiper a of the preselector VW, wiper a of the nal selector LW, contact 3h, winding I of relay A, battery, earth. Relay A energizes and closes the following circuit for relay H: earth, contact la, winding I of relay H, battery and earth. Relay H energizes and opens its contacts 3h and 6h and closes its contacts 5h and 2h. These contacts are made as make-before-break contacts, i. e., contacts 5h and 2h close before the contacts 6h. and 3h open, respectively. In place of relay A, relay H now holds up over the subscribers loop: earth, winding II of relay H, contact 5h, wiper b of the final selector, wiper b of the preselector, the subscribers loop, wiper a of the preselector, wiper a. of the nal selector, contact 2h, winding I of relay H, battery, earth.

On seizure, the slow-to-operate seizing relay C, is also energized over the c-lead and wiper c of the final selector. Before it energizes, however, the switching operations just described in which relay H became energized have taken place. 5 Relay C closes its contacts and l'lc and thereby switches through the leads of the connecting line VL to the incoming repeater Ue2 in the distant exchange. Since contact 14h has also been closed, the impulse receiving relay J in the l0 incoming repeater Uel is now energized over the a-lead: earth, winding of relay J, a-lead of the line VL, contact l6c and I 4h, winding of relay Dri, battery, earth. The control relay B of the incoming repeater U62 is energized over the b'- 15 lead: earth, winding of relay B, lead h, of the line VL, contact llc, winding of relay DTZ, battery, earth. The winding I of relay V of the repeater Uel is for the moment still short-circuited over contacts 8c and 9h.

When impulses are transmitted by the calling subscriber, the subscribers loop is alternately opened and closed. When the loop is opened relay H releases. It interrupts the circuit for the receiving relay J in the incoming repeater Ue2 25 at its Contact Mh. Relay J there extends the impulses in some manner with which we are not concerned, for example by breaking a loop. When relay H releases contact 2h and 5h are also opened and contacts 3h and lh closed. 30 When at the end of the impulse the calling subscribers loop is closed again, relay A rst energizes again over the loop. Relay A energizes rapidly. In the event of the closing of the loop which in the present-l embodiment represents the 35 impulse pause, being very short, the relay is held energized after its initial energization in the following circuit: earth, contacts lla, 3h, winding I of relay A, battery, earth. Relay A energizes and operates relay H over its contact la and 4 winding I. In addition it short-circuits its own winding III over contacts 1ct and the controlling resistance Wil. On account of this short circuit relay A is made slow-to-release and the extent of this effect can be adjusted by the variable 45 resistance Wil. After relay H has energized, relay A is disconnected from the subscribers loop and in place of it relay H is connected to the loop over its windings I and II. Since it has been assumed that the closing of the loop is very brief, 50 relay H will not be held over the loop but on account of the slow-to-release feature of relay A it remains energized at rst over contact la. Only when relay A has released does relay H deenergize and extend the impulse by opening its 55 contact Mh. Relay A is now reconnected to the subscribers loop in place of relay H.

If the next closing of the loop instead of being very short, as previously assumed, should be very long and the opening of the loop, i. e., the impulse should be short, relay A energizes rst and after its release relay H is held energized over the subscribers loop until the loop is interrupted. Since relay H is very quick to release, for example 5 ms. on account of a suitably arranged stop plate, and moreover after the interruption of the loop at rst only relay A enenergizes and then in dependence thereupon relay H, a sucient length is lgiven to the extended impulse in spite of a very short breakage of the loop.

What is claimed is:

1. In an impulse correcting repeater arranged to receive series of impulses over a circuit and transmit corrected series of impulses, an impulse receiving relay connected to said circuit and energized thereover, an impulse transmitting relay, a circuit controlled by the receiving relay for energizing said transmitting relay, and means controlled by the transmitting relay for discon necting the receiving relay from the circuit and connecting the transmitting relay thereto.

2. A repeater as claimed in claim 1 in which the impulse receiving relay shunts one of its windings to make it slow to release.

3. A repeater as claimed in claim 1 in which the receiving relay has means for locking itself over a local circuit, after it is energized over the rst circuit.

4. A repeater as claimed in claim 1 in which the receiving relay when closing the circuit of the transmitting relay shunts one of its own windings and closes a local locking circuit for itself.

BENEDIKT KUDRNA. 

